Also data access arrangement. An interface switching device that enable an operator to set up half-duplex data transfers on a dialed PSTN line.(Some devices provide for setting up full-duplex transfers on two dialed lines). Typical functions are to provide a connection for a telephone (used to set up data transfers), to witch between VDICE and DATA, and, usually,to provide automatic answering.; 也稱為數(shù)據(jù)存取裝置。一種接口交換設(shè)備,能使操作人員 在被撥號(hào)公用電話交換線路上建立半雙工數(shù)據(jù)傳輸(有些設(shè)備還允許在兩條被撥號(hào)線路上建 立全雙工傳輸)。典型的功能有: 為電話提供連接(用來進(jìn)行數(shù)據(jù)傳輸),在語言和數(shù)據(jù)之間進(jìn) 行轉(zhuǎn)換,以及提供自動(dòng)回答等。